Such a device is generally positioned under an interior trim element. The interior trim element has a window defined by a line of least resistance, and a peripheral region surrounding the window. In such an arrangement, the interior trim element covers the safety device to which the airbag is attached, with the window of the interior trim element facing the opening for deployment of the airbag delimited by the chute channel, and with the flap of the device being attached to the window of the trim element.
When the airbag is inflated, it first fills the volume defined by the inner walls of the chute channel and the flap to strike against the lower face of the flap, which causes the window to open along the line of least resistance. Next, the airbag passes through the window of the trim element and is deployed within the passenger compartment in order to protect the occupants.
Given the speed at which the flap opens, the extreme temperatures the safety device is subjected to, and the stresses applied by the airbag on the safety device, it has been noted that the hinge connection could partially or completely tear. If the hinge connection completely tears, the flap could be projected into the passenger compartment of the vehicle, towards the occupants of the vehicle.
To reduce this risk, a device is known, for example from document DE 103 06 385 A1, comprising a chute channel and a deflector connected to the chute channel, as well as a trim element in which a window is arranged, the window being connected to a peripheral region of the trim element by a hinge connection. During an impact to the vehicle, the airbag displaces the window to deploy within the passenger compartment of the vehicle. The hinge connection, protected by the deflector, allows the window to pivot relative to the chute channel while retaining the window, which prevents it from being projected into the passenger compartment where it could injure a passenger. With this type of device and arrangement, the hinge connection is incorporated into the trim element. The step in the device manufacturing process for incorporating the hinge connection into the trim element requires more complex tooling, which results in a less reliable and more expensive device. In addition, the incorporation of the hinge into the trim element can cause flaws on the upper part of the trim element, meaning flaws visible to the vehicle occupants, depending on whether the trim element is a piece covered with a thick covering layer or is a left bare piece, meaning uncovered or covered with a thin covering layer.